Efficient production of acetone butanol ethanol from sole fresh and rotten potatoes by various Clostridium strains

This study aimed to evaluate rotten potato in the fermentation of acetone butanol ethanol (ABE). For this purpose, three strains, Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422, were used and production experiments were performed in a simple media only composed of either fresh or rotten potato. Effects of potato concentration (100–400 g/L) and time (24–144 h) on the fermentation were determined using fresh potato. The highest ABE production was detected at 400 g/L potato concentration at the end of 96 h by all strains. Clostridium acetobutylicum DSMZ 6228 was the most efficient strain in producing ABE among the microorganisms tested. Total ABE productions by Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422 at 400 g/L in 96 h were 12.3, 17.6, and 12.0 g/L, respectively. The majority of the products was butanol that made up ca. 66–67% of total ABE. Significant amounts of ABE were also produced with rotten potato which was compatible with the results obtained with fresh potato. They were determined as 11.5, 17.1, and 9.6 g/L with Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422, respectively. The results showed that rotten potato could be a good candidate as substrate for ABE fermentation.